This invention relates generally to air conditioning systems and, more particularly to an evaporator coil having a single row of tubes.
An evaporator coil is ordinarily made up of a plurality of sections, with each section having two or more rows of tubes. The tubes are commonly interconnected at their ends by return bends such that one or more circuits are formed with a plurality of interconnected tubes such that, with the introduction of refrigerant into a first tube, the refrigerant flows successively through the tubes until it reaches a last tube, after which the refrigerant flow then passes out of the coil and is made to flow to the compressor.
An air conditioning system is so designed that the refrigerant passing into successive tubes gets progressively evaporated, and when it reaches the last tube, it is in a superheated vapor condition. The purpose of this is to protect the compressor by preventing any liquid refrigerant from passing to the compressor.
It is recognized that superheat tubes can potentially be above the air dew point temperature. Accordingly, humid air passing over the superheat tube is not dehumidified as is the air passing over the other non superheated tubes. If nondehumidified air is allowed to pass through the heat exchanger, it may cause a fogging effect downstream thereof. That is, as the high humidity air mixes with cold air downstream, fog can be generated, or condensation can form on cold surfaces. The result may be that fog and/or water is then blown into the conditioned space. With a coil of two or more rows, this problem is overcome by the fact that the air passing over the superheat tube has passed or will pass over a nonsuperheated tube from another row. Thus the air passing over the superheated tube is dehumidified by a nonsuperheated tube, and the fogging problem is averted.
For purposes of reducing cost and weight, it would be desirable to replace a multi-row, low fin density coil with a single row, high fin density coil. However, since there is no adjacent unsuperheated tube to dehumidify the air passing over the superheated tube, the problem of fog generation is present.
It is therefore an object of the present invention to provide an improved single row coil.
Another object of the present invention is the provision for overcoming the problem of fogging in a single row coil.
Yet another object of the present invention is the provision for reducing the flow of non-dehumidified air from a single row coil.
Still another object of the present invention is the provision for a single row coil which is economical to manufacture and effective and efficient in use.
These objects and other features and advantages become readily apparent upon reference to the following descriptions when taken in conjunction with the appended drawings.
Briefly, in accordance with one aspect of the invention, provision is made in a single row coil for the air flow to be diverted in such a way that the air being cooled and passing over a superheat tube in the circuit is also made to pass over a nonsuperheat tube such that the air is dehumidified prior to its passing downstream of the coil.
By yet another aspect of the invention, at least one baffle is placed near the heat exchanger superheat tube such that the incoming air flow is diverted to obtain the desired dehumidifying effect.
By yet another aspect of the invention, a pair of baffles are provided in the vicinity of the superheat tube, with one on each side of the tube row, and with the two being staggered such that the desired air flow diversion is obtained.
By still another object of the present invention, the diversion of air can be such that the air passes first over the superheat tube and then over a nonsuperheat tube or first over a nonsuperheat tube and then over a superheat tube.
In the drawings as hereinafter described, a preferred embodiment is depicted; however, various others modifications and alternate constructions can be made thereto without departing from the true sprit and scope of the invention.